1. Field of the Invention
The present invention relates to a setting tool having a housing, a bolt guide axially secured in the housing, and a press-on feeler displaceable in a direction opposite a setting direction against a biasing force of a spring.
2. Description of the Prior Art
It is conventional to provide in setting tools, which operate with high-pressure gases, press-on safety means that includes a press-on feeler that in the initial position of a setting tool, projects beyond the bolt guide of the setting tool in the setting direction. The press-on feeler is connected with a setting tool device that provides for feeding to the drive piston of the setting tool of high-pressure gases which are generated by a solid, liquid, gaseous, or powder propellant charge. This device is actuated when the setting tool is pressed against a constructional component, and the press-on feeler is displace into its press-on position. A setting tool of this type is disclosed, e.g., in German Publication DE 198 04 456.
The drawback of this setting tool consists in that the press-on feeler, which is formed as a sidewise accessible sleeve, can be displaced into its press-on position as a result of an unconscious hand manipulation, causing actuation of the high-pressure gas feeding device, without the setting tool being pressed against a constructional component.
Accordingly, an object of the present invention is to provide a setting tool of the type described above but with which the displacement of the press-on feeler into its press-on position as a result of an unconscious hand manipulation is not possible.
This and other objects of the present invention, which will become apparent hereinafter, are achieved by providing a setting tool having an axially displaceable safety sleeve that surrounds the press-on feeler and has an entraining surface facing in a direction opposite the setting direction and cooperating with a facing in the setting direction, counter-surface of the press-on feeler in a position of the safety sleeve in which its facing in a direction opposite the setting direction, free end surface engages the stop surface of the bolt guide, with a first distance between a setting direction-side, end surface of the press-on feeler and the counter-surface of the press-on feeler being greater than a second distance between a setting direction-side, end surface and the entraining surface of the safety sleeve, and with a sixth distance between the free-end surface of the safety sleeve and a setting direction side, end surface of the safety sleeve corresponding at most to a fifth distance between the end surface of the bolt guide and the stop surface of the bolt guide.
According to the present invention, the press-on feeler is formed as a sleeve arranged coaxially with the bolt guide. Manual displacement of the press-on sleeve into its press-on position in which the device for feeding propellant gases is actuated, is practically impossible as the press-on sleeve is surrounded by the safety sleeve. The safety sleeve, however, can be displaced in a direction opposite the setting direction manually until it abuts a stop surface provided on the bolt guide. Upon its displacement, the safety sleeve entrains the press-on sleeve. However in order to insure that the press-on sleeve is not completely displaced into its press-on position by the safety sleeve, in which the feeding of the propellant gases is initiated, the entertaining surface of the safety sleeve, which faces in the direction opposite the setting direction, is axially spaced from the counter-surface of the press-on sleeve in the initial position of the setting tool. Therefore, the press-on feeler is entrained only after the safety sleeve has been displaced a certain amount. The press-on feeler does not reach its press-on position when the safety sleeve abuts the stop surface of the bolt guide, and projects, in the setting direction, beyond the safety sleeve. However, the projected portion of the press-on feeler is not large enough to be grasped by a hand and be displaced in the direction of the press-on position of the press-on feeler. This excludes an unconscious actuation of a setting tool.
Only upon initiation of the press-on process, when the setting direction-side end region of the setting tool, the press-on feeler, the safety sleeve, and the bolt guide are pressed against a surface of a constructional component, the press-on feeler is displaced in its press-on position in which the propellant gases feeding device is actuated. In its press-on position, the press-on feeler is again completely surrounded by the safety sleeve.
In order to be able to keep the amount, by which the press-on feeler projects beyond the setting direction-side end surface of the safety sleeve after the safety sleeve has been manually displaced backward, very small, advantageously, a third distance between the setting direction-side, end surface of the safety sleeve and a facing in the setting direction, bearing surface of the safety sleeve is so selected that it corresponds at most to a fourth distance between the setting direction-side, end surface of the press-on feeler and a facing in a direction opposite the setting direction, support surface of the press-on feeler.
The entraining surface of the safety sleeve, which entrains the press-on feeler upon the manual displacement of the safety sleeve backward, in the direction opposite the setting direction, is advantageously formed by a flange-shaped, first projection provided on the outer profile of the safety sleeve.
In order to insure that a setting tool according to the present invention can be used in locations which are difficult to access, the diameters of the bolt guide, the press-on feeler, and the safety sleeve are so selected that radial distances therebetween in the setting direction end region of the setting tool are kept as small as possible. In order to insure the displacement of the press-on feeler relative to the bolt guide, despite a radial shoulder provided on the bolt guide, the tubular press-on feeler has two, following each other sections having different diameters. The second section of the press-on feeler, which adjoins the first section at its side facing in the direction opposite the setting direction, has an inner diameter that is greater than the diameter of the radial shoulder provided on the bolt guide. The transition region between the two sections is formed as a step with two circular surfaces, of which the surface that faces in the setting direction, forms a counter-surface that cooperates with the entraining surface of the safety sleeve.
The second circular surface of the transition region-forming step, which is located within the press-on feeler, preferably forms a support surface for a spring arranged in the tool housing for displacing the press-on feeler in its initial position after completion of each setting process and lifting of the setting tool off the constructional component.
In order to insure that in the initial position of the setting tool the end surfaces of the press-on feeler and the safety sleeve lie substantially in the same plane, the safety sleeve has preferably a bearing surface which is formed by a flange-shaped second projection provided on the outer profile of the safety sleeve and spaced form the first projection in the direction opposite the setting direction.
This bearing surface abuts, in the initial position of the setting tool, the facing in the direction opposite the setting direction, support surface of the press-on feeler.
The distance between the formed by the first projection of the safety sleeve, entraining surface and the formed by the second projection, bearing surface corresponds to a length equal to the difference between the first and second distances plus the wall thickness of the press-on feeler in the step-shaped transition region.
In order to insure that the amount by which the press-on feeler projects beyond the setting direction-side end surface of the safety sleeve after the safety sleeve has been manually displaced backward, is very small, advantageously, a length distance between the first and second distances and between the third and fourth distances corresponds to 0.1-0.5 of an outer diameter of the safety sleeve without the first and second projections.
The novel features of the present invention, which are considered as characteristic for the invention, are set forth in the appended claims. The invention itself, however, both as to its construction and its mode of operation, together with additional advantages and objects thereof, will be best understood from the following detailed description of preferred embodiment, when read with reference to the accompanying drawings.